100W Oz Bright Heat And Light Bulbs Produce Uvb, Uva, Light And Heat. These Bulbs Provide High Levels Of Uva And Uvb Making Them One Of The Most Effective Methods Of Simulating Natural Sunlight Plus Providing A Source Of Heat. Often Reptiles Under These Bulbs Will Have An Increase In Appetite And An Increase In Healthy Coloration. Oz Bright Heat And Light Bulbs Are Self Ballasted Mercury Vapor Bulbs So They Will Screw Into A Standard Socket. Mercury Vapor Bulbs Are Highly Recommended For Bearded Dragons, Monitors, Turtles, Water Dragons And A Lot More. Not To Be Used With A Thermostat Due To The Internal Ballast And Not For Use In Small Enclosures.